This invention is directed to balers for forming cylindrical bales hereinafter referred to as cylindrical baler and more particularly to such balers with a gauge for monitoring the uniformity of the diameter of the cylindrical bale during formation.
One conventional type of cylindrical balers generally comprises a crop pickup which delivers the crop into a bale-forming or baling chamber formed at least in part by a belt-type conveyor moveably mounted around transverse rollers. During formation the bale may be supported in the baling chamber either above the ground (off-ground rolled type) or on the ground (ground rolled type). The belt conveyor envelops at least a part of the upper portion of the bale to rotate the bale and the incoming mat of crop from the pickup into an increasingly larger cylindrical bale. After the bale reaches a predetermined size, the belt conveyor is pivoted away from the bale such that the bale may be discharged rearwardly from the chamber. Current commercial versions of such balers form bales ranging in size between 90 cm. to 170 cm. in width (measured along the longitudinal axis of the bale), 120 cm. to 210 cm. in diameter and 200 kg. to 1400 kg. in weight. The bales are typically stored unsheltered in the field and, thus, it is necessary that they be of a shape and density to retard spoilage due to weather.
A cylindrical baler of the ground-rolled type is disclosed, for example, in U.S. Pat. No. 4,012,892. Cylindrical balers of the off-ground, rolled type are disclosed, for example, in U.S. Pat. No. 3,931,702 and U.S. Pat. No. 4,150,527. Such balers are operated by being pulled by a tractor with the baling chamber aligned transverse to the direction of movement. The bale is started by feeding the windrow (usually between 60 cm. and 150 cm. in width) into the middle of the baler followed by feeding the windrow into one side of the baler and then the other to form a uniform diameter bale core in the bale-forming chamber. After the core is formed, the bale chamber is alternately fed on each side for longer periods of time to generate a bale of substantially uniform size and density throughout the formation process. Heretofore the determination of when the feeding of hay should be shifted from one side of the bale chamber to the other has been made by the operator turning around to face the baler from his position facing in the direction of motion of the tractor and observing the bale being formed in the bale-forming chamber. This method is inconvenient, lacks exactness, causes operator fatigue and relies on the experience of the operator to interpret correctly his observations relative to the uniformity of diameter of the bale being formed and to the need to shift from feeding of one side to the opposite side of the baling chamber.
In the event that a substantially uniform diameter of the bale is not maintained, an egg-shaped or pear-shaped bale is formed. This may allow or cause one of the outer belts of the upper conveyor adjacent the smaller diameter end(s) to fall off the end of the bale and jam the bale-forming chamber. In addition, the nonbalanced formation of the bale may also cause the formation of low density areas on the bale periphery which may lead to or cause premature deterioration of the bale during storage of the bale in the field. The deterioration is due to the fact that low density peripheral portions of the bale do not shed rain properly or as well as a bale of substantially uniform shape and density on the outer periphery of the bale exposed to the weather.